Sapphire Radeon HD 5870 Toxic 2GB Review

Closer Look:

If the box didn't say so, I would say that Sapphire's Toxic HD 5870 2GB card was the HD 5870 Vapor-X edition. The cards look identical in just about every way. The key words being just about! Under the hood you have the same 40nm Cypress core with 2.15 Billion transistors,1600 stream processors and 80 texture and 32 ROPs units cooled with Sapphires own Vapor-X cooling solution. Where you really see a difference, is when compared to the Vapor-X edition, the back side of the Toxic is covered with an embossed aluminum cooling plate that works to keep the additional 1GB of GDDR5 memory cool. This card supports PCIe 2.0, Win 7, Eyefinity,Stream Technology, DirectX 11 and is built using an in house designed and built PCB that uses proprietary components such as Sapphires "Black Diamond" chokes to allow the Toxic to run cooler and allow performance tuning. Coming in at 10.5 inches in total length from stem to stern, the actual length inside the chassis is 10 inches from the mounting bracket to the rear of the card, making this card easier to fit into a chassis than the 11 inch length of the reference version. Clock speeds on the Toxic have taken a significant swing upwards on the core to 925Mhz, from the factory default 850Mhz, while the 2GB of memory takes a small jump upwards to 1225Mhz.

Connectivity options on this card are standard fare for the HD 58XX series and include a single DisplayPort connection, 2 Dual Link DVI and a single HDMI connection that supports HDMI 1.3 and up to 7.1 high definition audio. This display configuration will allow you to run an Eyefinity multiple monitor setup with resolutions of up to 7680x1600. The back end of the Toxic is wide open to allow the Vapor-X cooling to breath cooling off the separate heatsink for the power regulation circuit. Another difference in this card when compared to the Vapor-X model is the use of a 6 pin + 8 pin PCIe power connection configuration, instead of the more common 6x6 pin design on the reference cards. This means that ATI recommends a power supply of at least 500 watts for single operation and 600 watts for a CrossfireX configuration with two cards. Of course that number will scale upwards if you add more HD 5870 cards to the mix. This card supports CrossfireX with up to a total of four cards but requires a motherboard equipped with four PCIe 16x slots.

The cooling system employed by Sapphire to cool down the Toxic 2GB card is their well known Vapor-X cooling solution. It employs their vapor plate technology along with heat pipes to transfer the thermal load from the core and memory, through the vapor plate to a series of heatpipes, to an aluminum fin array. To cool the mosfets in the voltage regulation circuit, you have an aluminum heatsink that bolts on and uses airflow generated by the fan to cool down this high temperature location on the card. The fan used in this cooling solution is manufactured by ADDA and is model number AD0912UB-U7BGL. This translates into is a seven blade, 92mm, DC brushless fan that operates on 12 volts DC, with ball bearings instead of a sleeve bearing. The closest comparison fan that I could find at ADDA's website lists fans that operate at around 3300 RPM and 60CFM at around 39dBA. When you spool up the fan speed to 100%, the rated noise specification sounds about in line with fans I have running at this noise level. When you adjust the fan speed downwards, the noise penalty diminishes quickly.

Once you strip the covering away and get to the bare PCB, you can see the memory arrangement on both the front and back sides of the PCB. The 40nm Cypress core runs at 925Mhz, a substantial increase over the factory clock speeds while the GDDR5 memory gets a smaller bump in clock speed to 1225Mhz, with a boost in capacity to 2GB. The GDDR5 memory used in this application is made by Samsung.

Sapphire uses proprietary components when they build their cards. One of the items that stands out is their "Black Diamond" chokes that run up to 10% cooler and 25% more efficiently than standard components. The power circuitry is located at the back of the card and is covered with a heatsink when in operation.

Besides the basics, the one thing the cards have in common is the method of cooling the onboard components. While the implementation may be slightly different, the effect is the same. Both start out with a flat vapor chamber that the memory and GPU core directly contact. From there, the solutions differ drastically. I will touch on that later, after seeing how the process works. The vapor plate is used to wick away heat, much the same way a heatpipe does. According to Sapphire's white paper on the vapor plate technology, the liquid inside the vapor plate is something we use each and every day - water, plain and simple. But, water boils at 212° F, right? Not when the pressure is reduced by pulling a vacuum. You can see the port where the vacuum was pulled, and the opening has been soldered shut to prevent vacuum loss. Rather than describe how the process works, I will let the blown-up images show just how simple the process really is. The technology works and has been effective at controlling the thermal load on everything from the HD 3XXX series, right on up to the current top of the line ATI based card the HD 5970 that comes with a vapor chamber cooling solution capable of dissipating 400 watts.